A so-called preparative separation chromatograph system for separately collecting one or more components contained in a sample using a liquid chromatograph or gas chromatograph has been commonly known. In those kinds of preparative separation chromatograph systems, an eluate fluid discharged from a column is fractionated and collected for a specific period of time by a fraction collector based on the retention time of each specific target component in the sample so as to isolate an eluate fluid containing that target component from the sample. The timing of separately collecting the eluate fluid containing the target component in such a preparative separation chromatograph system is determined by a manual or automatic process.
If a comparatively large amount of sample is available, it is possible to perform a preliminary chromatographic analysis for that sample to create a chromatogram and allow an operator to examine the chromatogram and determine the timing of fractionation. However, for example, if there is only a small amount of sample available or the sample is expensive and valuable, it is impossible to perform the preliminary chromatographic analysis, and the fractionation must be performed with a single chromatographic analysis.
Patent Literature 1 discloses a preparative separation chromatograph system which concurrently performs two modes of fractionations: a time-based fractionation, in which the operation of discontinuing one fractionation and proceeding to the next one is repeated at predetermined intervals of time, and a fractionation based on the peak detection, in which, when the beginning point of a chromatogram peak is detected, a fractionation for that peak is initiated, and when the ending point of that peak is detected, the fractionation is discontinued to proceed on to the next one. With this system, the component whose peak has been detected can be assuredly isolated by the fractionation, while other trace amounts of components whose peaks are undetectable can also be caught by one of the time-based fractionations performed a number of times.